Self-swabbing versus assisted swabbing for viral detection by qRT-PCR: the experience from SARS-CoV-2 based on a meta-analysis of six prospectively designed evaluations conducted in a UK setting

• Published in: European journal of clinical microbiology & infectious diseases 2024-08, Vol.43 (8), p.1621-1630
• Main Authors: Fowler, Tom, Chapman, David, Futschik, Matthias E., Tunkel, Sarah A., Blandford, Edward, Turek, Elena, Kolade, Olumide, da Cunha, Sergio Souza, Dodgson, Andrew, Klapper, Paul, Sudhanva, Malur, Davies, Lindsey, Hill, Sue, Hopkins, Susan, Peto, Tim
• Format: Article
• Language: English
• Subjects: Adult; Biomedical and Life Sciences; Biomedicine; COVID-19; COVID-19 - diagnosis; COVID-19 - epidemiology; COVID-19 - virology; COVID-19 Nucleic Acid Testing - methods; COVID-19 Testing - methods; Female; Humans; Internal Medicine; Male; Medical Microbiology; Nose - virology; Pandemics; Pharynx - virology; Polymerase chain reaction; Prospective Studies; Respiratory diseases; Reverse transcription; SARS-CoV-2 - genetics; SARS-CoV-2 - isolation & purification; Self testing; Sensitivity analysis; Sensitivity and Specificity; Severe acute respiratory syndrome coronavirus 2; Specimen Handling - methods; Statistical analysis; United Kingdom; Viral diseases
• ISSN: 0934-9723; 1435-4373; 1435-4373
• DOI: 10.1007/s10096-024-04866-z

Purpose In April 2020, the UK Government implemented NHS Test and Trace to provide SARS-CoV-2 quantitative reverse transcription polymerase chain reaction (qRT-PCR) testing for the public, with nose-and-throat swabbing for samples performed by trained staff. Self-swabbing (SS) would allow rapid scale-up of testing capacity and access. Six studies were undertaken to determine whether SS was as effective for detecting SARS-CoV-2 as swabbing performed by trained staff. Methods Six prospective studies were conducted between April–October 2020, using six swab/media combinations. Differences between assisted swabbing (AS) and SS were evaluated for concordance, positivity, sensitivity, cycle threshold (Ct) values and void rates. Statistical analysis was performed using 95% confidence intervals (CIs), paired t-tests and model-based methods. Results Overall, 3,253 individuals were recruited (median age 37 years, 49% female), with 2,933 having valid paired qRT-PCR results. Pooled concordance rate was 98% (95% CI: 96%, 99%). Positivity rate differences for SS (8.1%) and AS (8.4%) and differences in pooled sensitivities between SS (86%; 95% CI: 78%, 92%) and AS (91%; 95% CI: 78%, 96%) were nonsignificant. Both types of swabbing led to pooled void rates below 2% and strongly correlated Ct values. Age, sex and previous swabbing experience did not have a significant impact on concordance or sensitivity. Conclusion The UK adopted a policy to promote self-testing for SARS-CoV-2 based on data demonstrating equivalence of SS versus AS. Positive outcomes with SS are likely generalisable to testing for other respiratory pathogens, and we consider self-sampling and self-testing essential for future pandemic preparedness.